I use them often for just the purpose you seek. Don't know your soils or climatic conditions, but here in zones 6 & 7 they grow quickly, fill in nicely and so far have been pest and disease resistant. If you have the room, stagger your planting, and you can tighten them up to a 6' center, if you must plant in a straight line, perhaps 8'-9' centers would be more appropriate. They can be planted closer for quick or immediate effect, but they will not be able to grow as thick and full being crowded too closely.

I know that they aren't the same as leland cypress but I have lelands and they blow over bad I am alway stacking them. Are Green Giant Arborvitae better with that ? I think the lelands problem is a small root ball not sure thought. I was also told to top them out it would give the roots a chance to spread out and wind wind wouldn't blow them over as easy because they were shorter. Do you think it would be smart pulling them up and planting Green Giant Arborvitae?

Depending on the site conditions, especially the soil, you may have to stake regardless of the plants installed.

Leylands are a very shallow rooted plant with a very fibrous root system that does not take well to B&B production in larger sizes. Large Leylands that are container grown will usually outperform B&B material. A Leyland can be sheared and kept in line pretty well, but I would never advise topping as a way of stabilization. If the root ball is small, staking, hole preparation, irrigation and proper planting technique will serve you better. By reducing the leaf area, you will be reducing the plants ability to make food and create more of a struggle for the roots to regrow and anchor. You can run into the same issues with Green Giants if they are not prepared and shipped correctly, but I have not run into the same issues as with Leylands.

My Leland's were here when i bought the property. I believe they were container because I remember when they were planted (years ago when I was a boy) they were very small (1-2 feet). As for topping them out to late I did that this fall. They were close to 20 feet I took them down to about 12. To late to tell me that was stupid, but what can I do now, just hope for the best? Maybe keep up on fert.? I don't really like them anyway is there anything that you can suggest? It has to get at least 10 feet and not every be able to see through it (not any time of the year) and preferably fast / very fast growing. thanks

Post all the site conditions and a pic or two and Im sure we can find a solution. Leylands typically grow quickly and full, but do have that shallow rooting thing and they don't like wet sites. If you only need 10 feet, the leylands should get beyond that height quickly, as will Green Giants. I understand the thick year round screen, but what don't you like about the leylands? You may want to consider adding or replacing some of the leylands with more interesting plants that will perform the same task. You can add interest, variety and biodiversity for resistance to pest and disease problems.

I'll try to get some pics tomorrow. The site is wet alot of the time but i can't just and dirt now right? I just don't really like how they are always blowing over I have them at a couple of places I cut grass at the are dry alot of the time and they blow over there as well.So that is why I was thinking of changing. They were also planted out in the yard to far (there are 2 staggered rows of them and there is about 10-15 feet behind them until the property line) I was thinking of planting something behind them then when it reaches 10 feet pulling up the lealands but I am still undecided.

For a windbreaks, arbs are gererally the last thing I'd plant. In nature, they are gererally found in swampy areas with a lot of protection. In a windbreak setting, they are out in the open and more prone to dessication due to their flat leaf surface. They are also shallow rooted and prone to uprooting in high winds. Add in that they are multi stemmed and cannot take a heavy snow or ice load.

I prefer something along the line of a spruce or fir for a windbreak.

__________________
Mike
"the Constitution is a charter of negative liberties" Barack Hussein Obama

If you like the job Granholm is doing for Michigan, you'll love the job Obama will do for the U.S.

“The best argument against democracy is a five minute conversation with the average voter.” Winston Churchill